The use of product cushioning devices for shock sensitive products has been known for many years. Such devices are used for protecting the shock sensitive products in the event that they are dropped or mishandled during shipping. Some examples of product cushioning devices include tissue paper, shredded paper, bubble-pack and molded foamed polystyrene pellets.
As the requirement for better packaging and cushioning became more demanding, for example with the introduction to the market of complicated and expensive electronics such as hard drives, printed circuit boards, and the like, the requirement arose for more sophisticated and better shock absorbing cushioning devices.
Cost, of course, plays a role in the manufacture of such cushioning devices as well. It is in a manufacturer's best interest to keep costs as low as possible. Typically, molding techniques producing a unitary cushioning device may be more efficient and thus less expensive. Molding techniques allow one to create devices formed of a resilient plastics material in a variety of different shapes and sizes as may be desired depending on the application and use of the finished device.
However, present molding techniques, such as thermoforming, give rise to some problems during manufacture of the device. A typical thermo-forming machine has a male or female die or mold. The use of these basic molds permits shaping of the plastics sheet into various desirable shapes and sizes (depending on the product to be packaged and the outer packaging container). There will also be a choice regarding the material used as well as the thickness of the plastic material used. The decision is determined based on the end purpose to which the unitary product cushioning device will be put. These design parameters will produce product cushioning devices of various forms, each with some inherited differences. These differences create fundamental characteristics of various parts of the final product, some of these characteristics being advantageous, but some being quite disadvantageous.
In particular, the compression strength of the molded unitary device, and thereby its ability to withstand shock forces may vary as a function of these design parameters. For example, an uneven distribution of material resulting in a device with thin sides is especially problematic if the packaged product is subjected to impact, such as impact that can occur during shipping. Such impact can have a detrimental effect on the shock sensitive product, resulting in damage or breakage of the product.
Thus is it desirable to provide a unitary product cushioning device for protecting shock sensitive products during shipping that can be molded from a resilient plastics material.